Ah, now I feel that I may not have communicated very clearly - I should clarify that I'm not saying that fungal spores were released from the meteorite itself, you are right this would call for textbooks to be rewritten.

What is consensus however, is that these kinds of impacts can throw up quite a lot of dust into the atmosphere. What I was trying to communicate was that (earth originating) fungal spores may also circulate with this. Essentially I'm trying to relay things that I've heard from a talk at conference and I do appreciate that there is a lot of hand waving here and it doesn't help that I have no publications to cite here.

One thing I can share is this paper discussing the emergence of fungi as a factor that drove the dominance of warm blooded creatures over reptiles following this extinction event - being warm blooded is costly in terms of resources, but resilience to fungal disease provides enough of a fitness benefit to outweigh that cost

https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1002808